Crank shaft twisting machine



April 10, 1934. N. R. BUCKINGHAM 1,954,281

CRANK SHAFT TWISTING MACHINE Filed Jan. 18, 1950 2 Sheets-Sheet l ATTORNEY.

April 10, 1934- N. R. BUCKINGHAM 1,954,281

CRANK SHAFT TWISTING MACHINE Filed Jan. 18, 1950 2 Sheets-Sheet 2 i l l l A TTORNEY.

BY ZM Patented Apr. 10, 1934 UNITI-:D STATES PATENT OFFICE CRANK SHAFT TWISTING MACHINE Application January 18, 11930, Serial No. 421,635 6 Claims. (Cl. 29--6) crank.

Recently many improvements have been made in efficacious means for clamping and twisting crank shafts, one of such improvements being disclosed in the patent to Shaw No. 1,553,638 of i September 15, 1925 who discloses mechanism for twisting flat forged throws of the crank about an imaginary axis in alignment with certain axes of the crank. An improved crank twisting device is disclosed in the patent to Shaw No. 1,779,017, dated October 2l, 1930, wherein means are disclosed for positively clam-ping and locking the crank in position before twisting and for unlocking the twisting members before untwisting, the cranks being twisted about fixed centers in alignment with certain bearings of the crank.

It is the object of the present invention to provide an extremely simple means and method for automatically and hydraulically operating and controlling the operation of twisting mechanism similar to'that shown in said above mentioned Patent No. 1,779,017. Another importantfeature of the invention resides in the provision of simple and compact twisting members for both clamping and twisting parts of the crank. Othernovel features are embodied in details of cooperating elements of hydraulic mechanism for operating and controlling the operation of the clamping and twisting members.

In the drawings:

Fig. 1 isa fragmentary view, partly in section, showing the essential elements of my novel twisting block control structure and showing the position of a closed twisting block and relative parts in solid lines and the position of an open twisting block and relative parts in dotted lines.

Fig. 2 is a View similar tcFig. l, but illustrating the position of the `various elements when the closed twisting block has been moved to twisted position.

Figs. 3 and 4 areV diagrammatic views of modiiied linkage that may be utilized in addition to the hydraulic power applying means.

The structure ofv the present invention is particularly applicable to the twisting of crank shafts having a relatively large number of throws. However, inasmuch as the present invention is directed mainly to a novel form of'twisting block and the application of power thereto, it is believed that the invention willv be better understood by only disclosing a single twisting member and the novel manner of applying power thereto.

The ltwisting block shown may be generally designated 1 and preferably consists of a lower die block 2 for receiving the lower half of a part of the crank and an upper die block or cap 3 for clamping the upper half of the same part of the crank. The center of the twisting block maybe designated A and while this center may vary considerably depending upon the bearing about which the throw is to be twisted, it will be sufricient for the present embodiment of the invention to designate the central point as that indicated at A.

The lower half of the twisting element 1 preferably consists of an integral bracket member 4.

which is rigidly supported by a suitable cradle 5. This cradle 5 may extend the length of the twisting mechanism and carry a plurality of twisting members or a single twisting member as the case may be. The point is that this cradle member 5 terminates in suitable trunnions, shown in dotted lines in Fig. 1, which are preferably in axial alignment with the axis of rotation A of certain twisting members. Such trunnions are preferably at the ends of the shaft to be twistedJ and thus permit the use of a great number of relatively thin twisting members.

The upper half 3 of the twisting member is pivotally connected to the lower half 2 and the bracket 4 as at 6, and the upper half 3 is provided with a suitable arm 7 for pivotal connection with an actuating lever 8, such pivotal connection being designated B. The lever 8 is pivotally connected as at C to a bracket member 9 which may be fulcrumed as at D and actuated by means of a suitable piston rod 10 forming a part of a main hydraulic cylinder 11. This main cylinder member 11 may be pivotally mounted as at 12 to permit bodily movement thereof in actuating the member 9 about the fulcrum D.

It will be understood thataplurality of levers similar to the lever 8 may be connected to the bracket member 9 for actuating the caps of other y twisting members. Actuation of the piston 10 in one direction by the hydraulic mechanism 1l will open the twisting member so that the top half 3 of the twisting member is moved to the posisition shown in dotted lines in Fig. l, and actuation of this piston rod 10 in the other direction will cause the cap to close upon a part of the crankshaft and force the same home into position. As the cap 3 is closed, as shown in solid lines in Fig. 1, continued movement of the piston rod l0 will tend to twist the entire twisting member 1 about the trunnions which carry the cradle 5. This tendency to twist the entire member is temporarily restrained by a second power means which is pivotally connected to the cradle as at E and which may consist of a suitable piston rod 13 and cylinder 14 of smallei` bore than the main cylinder 11. This cylinder 14 is pivotally mounted similarly to the cylinder 11 so as to oscillate with movement of the cradle 5.

Suitable valve mechanism may be connected to each end of the cylinders 11 and 14 for actuating the piston rods therein. The structure oi such valve mechanism will be understood to those skilled in the art and it will be suflicient for the purposes of this invention that any suitable valve mechanism be provided which will operate the respective pistons within the cylinders in timed sequence.

In operation, with the parts as shown in dotted lines in Fig. 1, and the crank to be twisted positioned within the lower dies, power is applied to the upper end of the cylinder 14 to hold the cradle 5 in the position shown, the piston of the operating cylinder 11 being in its lowermost position whereby the pivot point B will be at a point B and the cap 3 in open position, as shown in dotted lines.

Power is then aplied to the lower end of the cylinder 11 whereby the piston rod 10 is moved upwardly. This action will cause the closing of the cap 3 to positively force the crankshaft into bottom position in the dies. As the eective area of the piston in the cylinder 1l is larger than that in the cylinder 14, it will be obvious that the swing frame or cradle 5 will be held in normal position until the power applied by the cylinder 11 is sufficient to overcome that applied by the piston rod 13. This relative application of power will cause the two halves 2 and 3 to be positively moved together under considerable pressure. Therefore, the auxiliary cylinder 14 will act as a locking means to thus positively prevent movement of the lower frame 4 and the twisting member as a whole until the two die halves are positively brought together to force the crankshaft home.

As the power of the operating cylinder overcomes the retarding effect of the cylinder 14, the entire twisting member 1 will twist about the center A. The cap is thus kept in a clamped position throughout the entire twisting operation.

When the piston rod 10 has reached the end of its stroke or a suitable stop has been provided so that the twisting member is twisted to its required position, that shown in Fig. 2, pressure is applied to the lower end of the cylinder 14 so as to hold the piston rod 13 in uppermost position, as shown in Fig. 2. Pressure may then be applied to the top of the piston l1 to force the piston rod 10 downwardly. This action will move the lever 8 from the position shown in Fig. 2 to that shown in Fig. 1 which will thus cause the cap 3 of the twisting member to be unclamped. Continued movement of the piston rod 10 will result in the part 15 striking the upper edge 16 of the cradle, and still further movement of the piston rod 10 will overcome the power applied by the piston rod 13 and will cause the unclamped twisting member to move back to the position shown in dotted lines in Fig. 1. It will thus be seen that the power applied by the cylinder member 14 will be effective to lock the lower half 4 in both normal and twisted positions until the positive clamping or unclamping operations are accomplished.

The greatest application of power is required just at the time of the final clamping operation. In twisting large crankshafts I may provide additional linkage such as illustrated in Figs. 3 and 4 to assist in the initial clamping action. For this purpose I may provide a bell crank member 20 which may be pivotally connected to the member '7 as at B, the ends of the bell crank being connected to the lever 8 and to a second lever 21 which is preferably connected to the cradle or base member as at E. It will be obvious that with this arrangement, upward movement of the lever 8 will cause the bell crank to approach the position shown in Fig. 3, and will therefore aid materially in assisting the clamping action between the two halves 2 and 3.

What I claim is:

1. In a crank twisting machine, a crank twisting member comprising a block formed of a pivotally mounted base and a cap pivotally connected to said base for clamping a portion of the crank into position in the base preparatory to twisting, an arm formed rigidly with the cap and directly connected to and extending past said pivot, power operated means adapted to engage said arm for moving said arm about the pivot for said cap as a fulcrum, said power means actuating said arm and clamping the cap on the base in the rst part of its movement and utilizing said clamping action to assist in twisting the entire member in the second part of its movement, and means connected to said base for temporarily preventing the movement of the base about its pivot.

2. In a crank twisting machine, a crank twisting member comprising a block formed of a pivotally mounted base and a cap pivotally connected to said base for clamping a portion of the crank into position in the base preparatory to twisting, an arm formed rigidly with the cap and directly connected to and extending past said pivot, power operated means adapted to engage said arm for moving said arm about the pivot for said cap as a fulcrum, said power means actuating said arm and clamping the cap on the base in the rst part of its movement and utilizing said clamping action to assist in twisting the entire member in the second part of its movement, and power means operating in a direction opposite said rst power means and tending to lock said member against rotary movement until overcome by the power means for closing the cap.

3. Crankshaft clamping and twisting mechanism comprising a pair of relative movable cooperating clamping and twisting elements one pivotally carried by the other, one of said elements consisting of a base member supported by a pivotally mounted cradle, means operating on said elements to relatively move the same and then cause their unit rotation including power means directly connected to said cradle and one side of the cradle pivot to hold the cradle fixed during clamping, a second power means connected to one of said elements on the same side of the cradle pivot as the connection of the first power means to the cradle,` the forces exerted by the rst and second power means on the cradle and element, respectively, during clamping and twisting being in opposite directions, said second power means operating to close the element i against the cradle during clamping, said cradle being held against movement by Said rst power means, said second power means overcoming the constant resistance exerted by the rst power means against turning of the cradle to move the element and cradle as a whole about the cradle pivot.

4. Crankshaft clamping and twisting mechanism comprising a pair of relatively movable cooperating clamping and twisting elements one pivotally carried by the other, one of said elements consisting of a base member supported by a pivotally mounted cradle and the other element comprising a cap, means operating on said elements to relatively move the same and then cause their unit rotation including power means directly connected to said cradle and one side of the cradle pivot to hold the cradle fixed during clamping, a second power means connected to said cap on the same side of the cradle pivot as the connection of the iirst power means to the cradle, the forces exerted by the first and second power means on the cradle and cap respectively during clamping and twisting being in opposite directions, said second power means operating to close the cap against the cradle during clamping said cradle being held against movement by said rst power means, said second power means overcoming the constant resistance exerted by the first power means against turning of the cradle to move the cap and cradle as a whole about the cradle pivot.

5. Crankshaft clamping and twisting mechanism, comprising a pair of relatively movable cooperating elements one pivotally carried by the other and supporting a crankshaft therebetween, one of said elements having a member integrally formed therewith and pivotally mounted upon an axis in alignment with a bearing of the crankshaft, the other element having an arm rigidly formed therewith and adapted to be actuated by a main operating means including power means directly connected to said cradle and one side of the cradle pivot to hold the cradle fixed during clamping, a second power means connected to one of said elements on the same side of the cradle pivot as the connection of the iirst power means to the cradle, the forces exerted by the rst and second power means on the cradle and element, respectively, during clamping and twisting being in opposite directions, said second power means operating to close the element against the cradle during clamping, said cradle being held against movement by said first power means, said second power means overcoming the constant resistance exerted by the iirst power means against turning of the cradle to move the element and cradle as a whole about the cradle pivot.

6. Crankshaft twisting and clamping mechanism, comprising relatively movable clamping and twisting members, one pivotally carried by the other, power means directly connected to one of said elements on one side of said pivot to hold said element fixed during clamping, a second power means connected to the second element on the same side of said pivot as the oonnection of the first power means to the first element, the forces exerted by said first and second power means on said first and second elements, respectively, during clamping and twisting being in opposite directions, said second power means during clamping being adapted to close the second element against the first which is held against movement by the rst power means, said second power means then overcoming the constant resistance exerted by the rst power means against turning of the first element to move the second element and first element as a whole about their common pivot.

NORRIS R. BUCKINGHAM. 

